Energy
Sustainable Floridians 2016 Class
Electricity 101
 Electricity, while often difficult to visualize due to its nature, is easy to grasp as it’s very similar to
water flowing through a garden hose
— Voltage (measured in volts) is analogous to water pressure (measured in pounds per square inch)
— Current (measured in amps) is analogous to the flow of water (measured in gallons per minute)
— Power (measured in watts) equals volts multiplied by amps
— Energy is an amount of power for a specified time, so volts x amps = watts, and 1 watt for 1 hour = 1 watt*hour
— We are billed approximately $0.10-0.12 per kWh, which is 1,000 watts for 1 hour
— Another way to think of it is 1 watt used 24/7 equals about $1 per year
 Cost to run various items
— A blow dryer may use 1,500 watts on high, running it for 10 minutes one day would cost
− 1,500/1,000 * 10/60 * 0.11 = $0.03
— An A/C unit may use 3,000 watts, running it for 4 hours one day would cost
− 3,000/1,000 * 4 * 0.11 = $1.32
— A new 50” LED TV may use 50 watts, running it for 4 hours per day over the year would cost
− 50/1,000 * 3 * 365 * 0.11 = $6.02
— An 800 lumen light bulb run for 4 hours per day over the year, would cost
− 60 watt incandescent – 60/1,000 * 4 * 365 * 0.11 = $9.64
− 13 watt CFL – 13/1,000 * 4 * 365 * 0.11 = $2.09
− 8 watt LED – 8/1,000 * 4 * 365 * 0.11 = $1.28
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Electricity “Vampires”
 Electricity “Vampires,” or vampire voltages, refer to devices that use electricity when sitting idle
and not performing their designed function
 Examples
— TV’s, DVD/Blu-ray players, computers, printers, etc. drawing current while turned off
— Anything that looks like these
— Vampires can easily use 1-10 watts each
 Most of us have many of these and the cost adds up fast
— Remember 1 watt used 24/7 costs about $1 per year
— Therefore 50 watts of vampires cost about $50 per year
— It’s likely 5-10% of your monthly electric bill is made up of these
AC/DC transformer (aka “power supply”)
 Unplugging is the least expensive way to save
 The easiest method is using a wall switch or a smart power strip
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Lighting
 There are three primary types of lighting technology
 Original bulb, light emitted from heated wire
 Very energy inefficient, generates mostly heat, 1-5k hour life
 Light emitted from vaporized mercury striking phosphor coating, hazardous waste
 75% less energy than incandescent, 5-40k hour life
 Electronic approach to generating light, very little heat, no hazardous waste, better quality of light
 90-95% less energy than incandescent, 25-200k hour life, dimmable, instant on, no cycling degradation
 LED has come a long way in recent years and has proven itself as a best practice
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HVAC
 Rule of thumb is that every 1 degree you change your thermostat (down when heating and up
when cooling) you reduce that portion of your energy bill by 3%
 Most of us are not in our homes 24/7, so significant savings can be had by adjusting the
temperature when you’re away
 A programmable thermostat makes this easy
— Doesn’t need to be expensive
— The Nest is great and does offer remote connectivity, but $30 can buy an effective programmable thermostat
that will save you pretty much the same amount as a Nest
 Recognize that the human body is quite adaptable
— While you may not be ready now to have a 76 degree setting in summer, moving it 1 degree a year will go
unnoticed by practically everyone and allow you to head in a good direction
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Water
 Saving water is often a win-win situation, because there are savings in the gallons reduced and
also savings in electricity and chemicals (e.g. well pumps, water softeners, hot water heaters)
 Two areas are easy to find savings in the home when focusing on energy to heat water
— Hot water heater temperature setting
− There are various conflicting reports when it comes to settings (120 or 140 degrees), but the WHO says 90%
of Legionella will die within 2 minutes at 140 degrees, in 80-124 minutes at 122 degrees, and survive but
don’t multiply at 118-122 degrees
− Additionally, the thermostats in water heaters are not known for their accuracy
− The suggestion I subscribe to is to set it to deliver 120 degrees at the farthest sink
— Shower heads
− Typical shower heads can be 3-5+ gallons per minute
− Low-flow shower heads can be found today that use 1.5-2.5 gallons per minute
− The complaints are of earlier models that didn’t work well in some lower pressure areas far away from a city
water tower, because what makes the most difference in how a shower feels is pressure (psi) not flow (gpm)
 It takes a lot of energy to heat water and, while situations vary, a good ballpark is around $0.020.04 per gallon for an electric water heater
— So, going from a 4 gpm to 2 gpm shower head would save 21,900 gallons of water annually for a family of 3
who each takes 10 minute showers daily, this could be around a $300 savings
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Summary
 Residential monthly electricity usage is 903 kWh nationally and 1,081 kWh in Florida
 My house at a glance
— 1,726 sqft ranch, CBS, single pane windows with blinds always open, asphalt roof, 2 adults, 1 child, and 2 dogs
that can’t decide if they want to be inside or outside
— Oct 15-Nov 15 bill (79 degree mean temp)
− Had just moved in, house contained incandescent and CFL lighting, fixed temperature thermostat, med-flow
shower heads (3.5 gpm), hot water heater 115 degrees at sink
− 1,235 kWh and $151.76
— Mar 15-Apr 15 bill (76 degree mean temp)
− Programmable thermostat, LED lighting, low-flow shower heads (2 gpm), hot water heater set to 120 degrees
at sink all implemented in December
− 894 kWh and $93.73 (kWh reduced by 28%)
— This is considered low-hanging fruit and $300 should yield about $300 in annual savings
− Programmable thermostat = $30
− 20 LED light bulbs = $200
− 2 low-flow shower heads = $70
− Adjust hot water heater to 120 degrees at farthest sink = free
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